JPH0678520B2 - Water stop method for concrete structure - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for stopping water in a concrete structure, and more particularly, to a foaming pressure due to a reaction between a hydrophilic one-pack type polyurethane prepolymer and water leakage in the concrete structure. The present invention also relates to a water stopping method, which comprises sealing and adhering a water leakage crack in a concrete structure by volume expansion.

(Prior Art) It is well known that moisture-curable polyurethane prepolymer is cured by reacting with water, and in the process of its chemical reaction, carbon dioxide gas is generated to cause foaming and volume expansion. It is said to reach 50Kg / cm ² or more when restrained. Utilizing this property, an injectant mainly composed of the prepolymer is injected as a water-stopping agent into a cracked portion of rock mass or a leaked portion of a concrete structure at a high pressure, and is rapidly cured by reacting with water. The water-stopping method of stopping water leakage by filling cracks and gaps in rock mass and concrete structures with the foam-hardened material has been conventionally performed.

However, this method simply utilizes the fact that the polyurethane prepolymer reacts and cures with water, and injects a large amount of the polyurethane prepolymer into the water leak surface of the concrete structure to rapidly cure the water so that the water leak surface of the concrete structure can be rapidly cured. To form a water-impermeable urethane resin cured product,
It is intended to obtain a water blocking effect by this hardened body, adhesion of fine cracks in concrete structure,
It is not intended to recover the physical strength and watertightness of the concrete structure itself, which is reduced by water leakage. Since it is expected that the water-blocking effect will be rapidly due to the formation of a cured product, it is a catalyst for increasing the reaction rate of the polyurethane prepolymer with water in the injectant, and foaming promotion for ensuring large foaming. Agents are being actively added.

Therefore, while the hardened body is rapidly formed on the surface layer of the concrete structure, fine cracks are left as they are without entering the inside of the concrete structure.

(Problems to be solved by the invention) That is, in the conventional water stopping method as described above, injecting a large amount of the injecting agent to the leaking surface of the concrete structure in order to allow infinite injection of the injecting agent. It is uneconomical because it is difficult to determine and confirm the required amount of the injection agent over the entire leak surface of the concrete structure; Has ended up,
Water-stop curing cannot be achieved due to the formation of a hardened body; due to the large amount of foaming due to the added foaming accelerator, the volume will decrease when water is lost, and the water-stopping effect will be lost; Due to the rapid hardening of the surface layer, the internal leakage cracks remain unsealed and unbonded; the concrete structure itself does not recover its strength or restore its watertightness.

There was such a problem.

It is an object of the present invention to solve the above problems in the conventional water stopping method, and to provide a water stopping method that is economical and reliable and that also restores the strength and water tightness of the concrete structure itself. It is a thing.

(Means for Solving Problems) Therefore, the present inventors have completed the present invention as a result of repeated research to solve the above problems.

That is, the present invention provides an injection hole for injecting a water-stopping injection agent, which will be described later, into the surface layer of the concrete structure by forming a hole along the water leakage crack of the structure and forming the hole-forming part. Forming a closed chamber for sealing the upper surface of the drilled hole to retain the water-stopping injection agent described later, and then forming a hydrophilic one-component polyurethane prepolymer mainly from the injection hole into the closed chamber. By injecting a predetermined amount of a water-stopping injection agent as a component, closing the injection hole, and holding and leaving the water-stopping injection agent in the closed chamber, the hydrophilic one-pack type polyurethane prepolymer is added to the concrete. The water-tightness of the concrete structure can be improved by gradually reacting with the water leak in the structure, and by the foaming pressure and volume expansion thereof, infiltrating and hardening into the space between the water leak cracks in the concrete structure and sealing and adhering the cracks. Restore and restore strength Which is a method for stopping water concrete structure characterized.

In addition, in the present invention, it is also possible to add cement or water glass to the hydrophilic one-component polyurethane prepolymer of the water-stopping injection agent and use it.

(Example) Hereinafter, the present invention will be described in more detail with reference to FIG. 1 which is a process chart showing an example and FIGS. 2A to 2K which schematically show each process. . First, in the groundwork treatment (1), the leaking surface of the concrete structure to be repaired is cleaned to remove the adhered substances, unnecessary substances, the waterstop applied before,
Remove water stains, moss, and alkaline products to expose the concrete surface.

Next, in the water leakage location investigation (2), the location of the water leakage is accurately searched for and the leakage state is checked and marked.

This is necessary in order to minimize the amount of the injection agent according to the present invention used, and the specific method may be the method used in the conventional repair of concrete structures.

Next, in the drilling operation (3), drilling is performed in the central portion of the water leakage crack 21 within a range that does not affect the strength considering the thickness of the concrete.

FIG. 2 (A) shows the drilling work at this time, and FIG. 2 (B) shows the drilled state.

Next, in attaching (4) the injection pipe for the water-stopping injecting agent, a hollow copper pipe or an aluminum pipe is inserted as the water-stopping injecting agent injecting pipe 22 into the drilled hole (see FIG. C)) The surrounding area is built up and fixed with a quick-setting agent 23 such as a quick-setting mortar to form a closed chamber 24 at the leak point (Fig. 2 (D)). In this state, the leaked water has leaked to the outside through the injection pipe 22,
No water pressure is applied to the mortar bonded part that has been fixed. In this state, the fixing mortar is left to stand until the strength of the fixing mortar appears.

Next, in the injection terminal attachment (5), after confirming that the quick-cure compound 23 fixing the injection tube 22 has been surely hardened, a connection terminal (nipple) 25 for injecting the injection agent is attached to the tip of the injection tube. . (FIG. 2 (E)) Next, in the injection agent injection (6), the injection port of the injection pump 26 is connected to the connection terminal 25 and the injection agent is injected while applying pressure (FIG. 2 (F)). The infusion pump 26 may be airless or plunger type, but it must be equipped with a gauge to check the infusion pressure. However, the pouring in the present invention does not force the pouring agent into the cracks of the concrete structure by the mechanical pressure of the pump, but only the foaming pressure by the chemical reaction between the permeated water and the pouring agent. Since the purpose is to inject the injection agent even into small cracks and capillaries in the object and solidify and bond all the cracks, the injection amount of the injection agent may be the volume of the drilling hole and the amount filled in the cracks near the drilling hole. , Does not require injection at high pressure. 6 at a pressure of 1 Kg / cm ²
Hold it for about 0 seconds and stop the injection if the pressure does not drop. If the pressure drops, repeat the injection under the same conditions.

Next, in the injection tube seal (7), the injection tube of the pump is removed from the injection tube terminal after the injection, and the injection agent is completely sealed so as not to flow out. For this purpose, the injection pipe may be crushed and bent, or the injection terminal provided with a backflow prevention device may be used. Immediately after the injection, the injection agent 27 has hardly penetrated into the water leakage crack (Fig. 2 (G)).

Leave in this state for several days. During this period, water (Fig. 2 (H)) that has propagated through small cracks and capillary cracks in the concrete chemically reacts with the injected injecting agent to foam and gradually increase in volume. It penetrates into cracks and capillary cracks (FIG. 2 (I)) and hardens, and the cracks are sealed and adhered. The time taken for the cured product to be formed by the chemical reaction between the injecting agent and water naturally varies depending on the type of the injecting agent, but generally 3 to 6 at room temperature.
It is time, and the strength of the cured product increases over the next 3 weeks. Therefore, in the present invention, it is preferable to set a curing time of at least 10 days. This is the biggest difference from the conventional water stopping method by the injection method. The conventional injection method is to rapidly cure water and the urethane prepolymer to complete the water stop, so that the prepolymer can be broken into small cracks in the concrete in a short time before the prepolymer is cured. It was difficult to apply a strong pressure enough to inject the water, and it was impossible to completely stop the water due to the generation of new cracks and a new water leakage channel due to the water channel being closed. Therefore, the conventional method cannot deal with water leakage that oozes out over a wide area or the entire surface.

On the other hand, according to the present invention, when water seeps out due to the capillary phenomenon, the water and the injecting agent that have been injected slowly undergo a chemical reaction to cause volume expansion, and all fine cracks and capillaries are formed. It is possible to completely stop the water because it is filled with an injection agent and hardened. In addition, the injected injection agent is completely closed at the injection port, so that it remains trapped in the concrete structure and cannot be washed away. In this way, since the injecting agent invades in the direction of the permeated water by the foaming pressure, the resin may be ejected to the surface through small cracks in the concrete structure, but it is left as it is. Water leakage does not stop until the curing time of the infusate arrives, but it gradually stops when the curing time comes (FIG. 2 (J)).

If water leakage is observed within a few days to 10 days or more after all the above work is completed, repeat the above work again at the leaked location.

Finally, in the post-treatment (8), after the water stoppage is recognized, the injection pipe is cut, the surface treatment 28 is performed, and the whole work is completed (FIG. 2 (K)).

In the above example, when there is very little water leakage at the water leakage point of the concrete structure, it is preferable to add water to the water leakage point to wet it.

The water-stopping injection agent according to the present invention contains a hydrophilic one-pack type polyurethane prepolymer as a main component, and this hydrophilic one-pack type polyurethane prepolymer has a property of reacting with water to foam and solidify. And has an isocyanate group, for example, polyalkylene glycol, polyalkylene glycol alkyl ether, polyalkylene glycol aryl ether, polyalkylene glycol alkyl aryl ether, or a mixture of polyalkylene glycol and organic acid ester of polyalkylene glycol. It is a reaction product obtained by reacting with an organic compound.

Here, the polyalkylene glycol, polyalkylene glycol alkyl ether, polyalkylene glycol aryl ether, and polyalkylene glycol alkyl aryl ether are polymers of ethylene oxide or propylene oxide or copolymers thereof, and have a molecular weight of 1,000 to 10,000. The organic acid ester of polyalkylene glycol is a polycarboxylic acid ester of the polyalkylene glycol, and specific examples of the polycarboxylic acid include maleic acid, adipic acid, phthalic acid and the like.

The compound having an isocyanate group that reacts with the above polyalkylene glycol, polyalkylene glycol alkyl ether, polyalkylene glycol aryl ether, polyalkylene glycol alkyl aryl ether, or a mixture thereof with an organic acid ester of polyalkylene glycol, is an isocyanate. Examples of the compound having at least two groups include tolylene diisocyanate, methylene diphenyl diisocyanate (polymethylene polyphenylene isocyanate), xylylene diisocyanate, and hexamethylene diisocyanate. Of these, tolylene diisocyanate and methylene diphenyl diisocyanate are preferable for controlling the solidification rate. The ratio of polyalkylene glycol, polyalkylene glycol alkyl ether, polyalkylene glycol aryl ether, polyalkylene glycol alkyl aryl ether, or a mixture of polyalkylene glycol and an organic acid ester of polyalkylene glycol, and an organic compound having an isocyanate group is The former is preferably reacted in the range of 1 to 10 isocyanate groups per hydroxyl group. It is not preferable to react the former hydroxyl group at a ratio of less than 1 isocyanate group per one, because the degree of polymerization is lowered and the solidification property is poor, and if it is 10 or more, the polymerization rate becomes faster and the solidification rate can be controlled. It is not preferable because it is difficult. As a reaction method, a known method is generally used.

Further, the degree of foaming reaction of the hydrophilic one-pack type polyurethane prepolymer used in the present invention can be adjusted by adding and using cement as an injecting agent. In order to suppress the foaming and to achieve the object of the present invention, the cement addition amount limit is preferably about 2.2 times the weight of the polyurethane prepolymer. In this way, it is recognized that the combination of cement and polyurethane prepolymer has mutually complementary effects, which indicates that both cement and polyurethane prepolymer have the property of being reactively cured by water, and that water is a common reactant. it is obvious. The cement absorbs the gas generated from the polyurethane prepolymer by adding water, so if the cement and polyurethane prepolymer are mixed in advance and water is added to this to start the curing reaction together, they will have their respective characteristics. It becomes a cured product, which is an advantageous material combination that improves the quality by interacting with each other to improve the physical properties.

In addition, as the water-stopping injecting agent according to the present invention, various materials conventionally used as an injecting agent, such as water glass and other alkaline substances, are added as long as the object of the present invention is not impaired. It is clear to get.

The reaction formulas for foaming and curing reaction of the urethane prepolymer with water are shown below for reference.

(Effects of the Invention) As is clear from the above description, the present invention provides an excellent water stopping method having the following effects.

． A closed chamber in which a hole is formed by drilling from the surface along a water leakage crack of a concrete structure, and then the upper surface is sealed while the hole is formed as an injection hole and the water-stopping injection agent is retained. Then, a predetermined amount of a water-stopping injection agent containing a hydrophilic one-component polyurethane prepolymer as a main component is injected from the injection hole into the closed chamber, and the injection hole is closed to stop the water injection. When the agent is retained and left in the closed chamber, the injecting agent foams and hardens by reacting with water leaking through the cracks in the concrete structure.

Therefore, after blocking the injection hole, the water-stopping injectant is retained and left in the closed chamber only during the period in which the water-stopping injectant reacts with the leak water to foam and harden. ,
The infusate is automatically tracked in and all leak cracks are sealed and glued by the infusate.

． The injection amount of the water-stopping injection agent only needs to be injected a little more than the volume of the closed chamber formed by drilling in the concrete structure, so the injection agent amount can be accurately confirmed, and more than necessary. It is economical because it does not require injection of the injection agent.

． Since the injection of the water-stopping injection agent is carried out in the hole-sealing closed chamber formed on the surface side of concrete or rock, it is not lost by running water and its effect is reliable.

[Brief description of drawings]

FIG. 1 is a process drawing showing one embodiment of the water stopping method of the present invention, and FIGS. 2 (A) to (K) are schematic diagrams for explaining each process of the embodiment of the present invention. 21: Water leakage crack, 22: Injection pipe, quick-setting agent: 23 24: Closed chamber, 25: Connection terminal 27: Water-stopping injection agent

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location E21D 11/38 Z 7265-2D (72) Inventor Bunji 2-16-1 Kyobashi, Chuo-ku, Tokyo No. Shimizu Construction Co., Ltd. (72) Inventor Shigeo Shimizu 1-2-4 Nihombashi Hamacho Chuo-ku, Tokyo Hamacho Building 502 Syntec Co., Ltd. (56) Reference JP-A-51-131139 (JP, A) JP 50-14124 (JP, A) JP-A 51-47949 (JP, A) JP-A 60-235863 (JP, A) JP-B 43-17598 (JP, B1)

Claims (2)

[Claims] 1. A pouring hole for boring a surface layer of a concrete structure along a water leakage crack to form a boring portion, and then pouring a water-stopping injection agent described later into the boring portion. Forming a closed chamber for sealing the upper surface of the drilled hole to retain the water-stopping injection agent described later, and then forming a hydrophilic one-component polyurethane prepolymer mainly from the injection hole into the closed chamber. By injecting a predetermined amount of a water-stopping injection agent as a component, closing the injection hole, and holding and leaving the water-stopping injection agent in the closed chamber, the hydrophilic one-pack type polyurethane prepolymer is added to the concrete. The water-tightness of the concrete structure can be improved by gradually reacting with the water leak in the structure, and by the foaming pressure and volume expansion thereof, infiltrating and hardening into the space between the water leak cracks in the concrete structure and sealing and adhering the cracks. Specializing in restoring and restoring strength Waterproofing method of the concrete structure to be. 2. The injection of a water-stopping injection agent from the injection hole into the closed chamber is performed from an injection pipe attached to the injection hole, and the injection hole is closed by sealing the injection pipe. A method of stopping water for a concrete structure according to claim 1.